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AMBIENT TEM PERATURE , FOOD AND FORAGING ACTIVITIES OF WAPITI, GERVUS ELAPHUS, NELS0NI.IN ASPEN BOREAL FOREST

JIANG Zhi gang Robert J.Hudson   

  • Online:2006-04-12 Published:2008-07-07

寒带针阔混交林中美洲马鹿的昼夜采食节律与食物、气温的关系

蒋志刚 Robert J·Hudson   

  1. 加拿大阿尔伯达大学,埃德蒙顿

Abstract: Activity rhythms of wapiti in aspen-boreal forests are polyphonic with fewest feeding bouts in mid-winter and summer(5.6d)and most frequent feeding bouts in spring(9.2d). Digestive kinetics. forage quality and availability as well as ambient temperature emerged as key factors regulating seasonal feeding rhythmsForage availability influenced intake rate hence feeding bout length whereas food quality determined passage and digestion rates. Rumen repletion and depletion set the base line for hunger and the desire to eat. When high quality forage was available in late springwapiti had a polyphasic foraging pattern (evenly distributed multiple foraging bouts)Howeverhigh ambient temperature suppressed feedingDuring mid-day in summer. inducing a crepuscular foraging pattern. Wapiti were able to compensate in subsequent foraging bouts for foraging time lost due to extreme ambient temperatures.

Key words: Wapiti ( cervu selaphus relsoni) Activity rhythm, Aspen boreal

摘要: 野生反刍动物一天中大部分时问用于摄食与反刍。为了适应采食生态环境与食物类型,野生反刍动物的行为表现出高度可塑性。反刍动物的采食活动节律受到食物摄入速率和消化能力的影响。摄入速率又受食物丰度、分布和动物的采食经验的影响。动物的消化能力则与食物质量、消化性能、排空速率以及消化道的充盈程度有关。一年四季中,美洲马鹿( cervus elaphus relsoni)的采食频次和持续时问变化很大。在加拿大阿尔伯达中部的针阔混交林中,我们研究了食物质量和丰度、气温对美洲马鹿的昼夜采食节律的影响。食物丰度影响了摄食速率。食物质量决定了消化道内容物的排空速率和消化速率。春天,当气温适中,可消化性高的青草茂盛时,美洲马鹿具有多相采食活动节律(较均匀分布的多个采食周期)。此时,瘤胃的排空可能引发采食。夏天,午间高温抑制了采食活动。此时,美洲马鹿的采食活动呈双峰型。冬天,尽管美洲马鹿的采食量下降,由于食物的纤维素含量高,美洲马鹿仍花费较多的时间反刍咀嚼,但这些活动多集中于气温较高的午间。极度低温会抑制美洲马鹿的摄食。而当气温回升后,美洲马鹿会补偿性地延长采食时问。美洲马鹿的昼夜采食节律季节性变化是其适应北方寒带气候和觅食环境的生态行为机制

关键词: 美洲马鹿, 活动节律, 寒带针阔混交林